Explanation:
Where did these two irregular moons of
Uranus originate? Last week two
previously undiscovered moons of the distant gas planet were
confirmed,
the first in irregular orbits.
All fifteen
previously known moons of
Uranus
are 'regular', circling near the planet's equator.
Most of these were discovered by the passing
Voyager 2 spacecraft in 1986. These newly discovered moons are thought to be odd-shaped and
about 100 km across. They are considered irregular, though,
because they orbit in odd directions and far from
Uranus. If Uranus' irregular moons
have the same origin as those orbiting
Jupiter,
Saturn,
and Neptune, then they were probably caught from orbits around the
Sun. Moons like this are discovered by their motion.
One of these moons is
shown above
as the circled point of light moving from left to right.
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